Dinosaurs

Some dinosaurs were herbivores (eating only plants), others were carnivores (eating animals including other dinosaurs), and some were omnivores who ate both meat and plants (these were mostly scavengers).

Different species of dinosaur ate many different things, depending on their size and adaptation to the environment. Pretty much anything alive (even non-organic matter, such as stones and rocks) was likely to find its way into the stomach of a dinosaur. The size of the largest herbivores and carnivores meant that they had ravenous appetites.

A dinosaur's diet depended on their digestive system, their size, and what kind of food existed at the time. For example, small herbivores would find it impossible to reach the leaves of tall trees, and therefore subsisted on shrubs and low bushes.

Well, different dinosaurs ate different things. Theropods, like T-Rex, Spinosaurus, and Allosaurus ate other dinosaurs or large animals. Here, let me show you some of these Theropod's top prey:

T-Rex-Triceratops, Parasaurolophus, etc.

Spinosaurus-Large Fish or medium-sized dinos

Allosaurus-Juvenile Sauropods, Stegosaurus, other Allosaurus, etc.

And then there were the Sauropods, Stegosaurs, Ceratopsids, Duck-Bills and other that ate plants, and sometimes rocks to help them digest food, like today's birds.

Finally, there were scavengers like Velociraptor, Utah Raptor, Deinoychus, Coelophysis, Dilophosaurus, Oviraptor, Compsognathus and Trodon, who ate eggs, small mammals, medium or small dinos, each other, bugs and more, and they usually hunted in packs.

There were many types of dinosaurs, and they had an equal variety of diets. Some, such as Tyrannosaurus rex and Allosaurus were large meat eaters that ate plant eating dinosaurs. Others, such as Spinosaurus, waded in swamps and ate fish. A few ate insects, such as Compsagnathus. Some, such as Oviraptor and Ornithomimus, ate both plants and animals. Last, but by far the most common, were plant eaters, including Triceratops, Stegosaurus, Ankylosaurus, and Apatosaurus (sometimes called Brontosaurus).
Carnivorous dinosaurs like Tyrannosaurus rex or Albertosaurus ate meat, including other dinosaurs. Herbivore dinosaurs like Brontosaurus or Diplodocus ate vegetation. Omnivore dinosaurs ate both meat and plants.
Dinosours ate leaves from trees or shrubs, (if they were a herbavore), and smaller creatures (if they were a carnivore).
Carnivorous dinosaurs like Tyrannosaurus rex or Albertosaurus ate meat, including other dinosaurs. Herbivore dinosaurs like Brontosaurus or Diplodocus ate vegetation. Omnivore dinosaurs ate both meat and plants.
Dinosours ate leaves from trees or shrubs, (if they were a herbavore), and smaller creatures (if they were a carnivore).

No, no dinoasur fosils were found since 65 million years ago, suggesting they were all killed off. Humans came no more than 7 millon years ago.

An asteroid impact killed the dinosaurs. This is the most widely accepted reason.

The theory: A large asteroid struck Mexico, forming a 240 kilometre wide crater. Resulting debris created a deposit of white powder in the atmosphere. This 'nuclear winter' blocked out the sun, killed plants, then plant-eaters and, finally, meat-eaters. How likely? Those dismissing the theory claim that smaller reptiles like turtles, alligators and crocodiles would also have been harmed; others argue the crater simply wasn't large enough to have caused such devastation.

Comet and cosmic rays killed the dinosaurs.

The theory: A massive comet travels close to Earth every 26 million years, bringing with it radioactive debris that collides with our planet, disrupting weather patterns and wiping out entire species, just as it did the dinosaurs some 65 million years ago. How likely? We have no concrete evidence of extraterrestrial events occurring at the point of dinosaur extinction. Furthermore, dinosaur remains show no evidence of radiation damage.

Volcanos killed the dinosaurs.

The theory: Western India saw huge volcanic eruptions which unleashed enormous quantities of lava, blocking out the sun, causing widespread climatic change and wiping out the dinosaurs. How likely? Deadly iridium in the Earth's 'K-T boundary' could conceivably have been caused by lava eruptions. However, scientists have widely agreed that 65 million years ago there was a global fall in temperature; a volcanic eruption would have had the opposite effect.

An ice age killed the dinosaurs.

The theory: Ice ages have occurred throughout Earth's history, with the last one ending about 10,000 years ago. A very severe ice age altered climates and froze waters to the extent that dinosaurs were unable to weather the conditions, and slowly died out. How likely? This theory has been largely discarded for one simple reason: scientists have not found a single scrap of evidence of an ice age occurring during the life of the dinosaurs.

Hay fever killed the dinosaurs.

The theory: Flowering plants known as angiosperms arose around 65 million years ago, creating a mass allergic reaction among dinosaurs. How likely: Not very! Flowering plants were around for millions of years before the dinosaurs disappeared and we have no evidence whatsoever that their pollen was capable of killing the dinosaurs. Plus this wouldn't explain the massive marine extinction - there have never been any marine angiosperms.

Obesity killed the dinosaurs.

The theory: The dinosaurs got too big and heavy, so much so they couldn't move about, defend themselves or withstand their own weight! How likely? There is absolutely no evidence to suggest the dinosaurs became so large and cumbersome that they couldn't move. Simply put, it is an evolutionary impossibility. Besides, most dinosaurs around by the end of the Cretaceous period were of medium or small size.

Mammals killed the dinosaurs.

The theory: The ecosystems of Earth 65 million years ago were such that mammals were out-competing the dinosaurs for food and space. How likely? Evidence points to a simultaneous evolution in dinosaurs and mammals, and some believe mammals did eat dinosaur eggs. But it's unlikely that mammals and dinosaurs had similar diets, so competition wouldn't have occurred. And there were no marine mammals at the time, so they couldn't have wiped out marine reptiles.

Disease killed the dinosaurs.

The theory: Towards the end of the Cretaceous period, land bridges opened up between places such as Asia and North America, allowing species to migrate. This led to a spread of disease to which other animals were not resistant. How likely? It could happen - Native Americans were nearly wiped out by smallpox, while the European invaders were resistant. But this argument fails to explain the disappearance of a multitude of species that lived in the sea.

Climate change killed the dinosaurs.

The theory: Earth gradually changed in climate over a long time period and the dinosaurs were not able to adapt to the cooler, drier climate. How likely? Climate change could have come about because Earth somehow tilted over about 23.5 degrees around 65 million years ago. How likely? Tilting could have occurred but what could have caused it. Asteroid impact? Debris from a passing comet? Scientists have never been able to answer this question.

Nothing killed the dinosaurs, they evolved!

The dinosars weren't killed they evolved!

The theory: Dinosaurs were not wiped out, they evolved into birds. There were certainly feathered dinosaurs and early birds resembled small meat-eating dinosaurs. Could it be that dinosaurs still walk - or fly - among us? Most scientists agree there is considerable evidence for many species of carnivorous theropod dinosaurs such as Velociraptor evolving into birds. But not all dinosaurs evolved into birds; Tyrannosaurus Rex died out with no evolutionary trace.

All birds evolved from the raptor family of therapod dinosaurs.

Looking back in time through the theropod fossil record, these dinosaurs appear to be more bird-like the further back in time you look. Raptors are known to have had feathers and were fairly bird-like, but Archaeopteryx was much more bird-like and lived much earlier and may have been an ancestor of the raptors. There is also a controversial fossil called Protoavis that was dated even earlier and was more bird-like still, with hollow bones like modern birds.

So birds may have been around throughout the mesozoic era and pre-date the dinosaurs. We have little record of them though because their hollow bones mean that few fossils survive to the present day.

The birds are the direct descendants of the dinosaurs.

Looking back in time through the theropod fossil record, these dinosaurs appear to be more bird-like the further back in time you look. Raptors are known to have had feathers and were fairly bird-like, but Archaeopteryx was much more bird-like and lived much earlier and may have been an ancestor of the raptors. There is also a controversial fossil called Protoavis that was dated even earlier and was more bird-like still, with hollow bones like modern birds.

So birds may have been around throughout the mesozoic era and pre-date the dinosaurs. We have little record of them though because avian bones are generally too fragile to leave fossils.

Not, as you might suspect, the biggest dinosaur. The giant sauropods had heads only about as big as those of horses. Though they ate prodigiously, they didn't need big chewing muscles because the real work of masticating food was done in their gizzards.

Counting bony projections, the biggest head belongs to Triceratops horridus, a comparatively compact, elephant-sized dinosaur.

The first creature to fly during the age of the dinosaurs was a kind of hybrid reptile/bird called Archeopteryx. Most people think of the Pterodactyl as the "flying" dinosaur, but Pterodactyls did not fly - they glided. Flying means that the creature could lift itself into the air under it's own power - they could not do that. Jumping off from a high point, they could glide very well, though.

The "flying squirrel" of today is similar - it glides, it does not fly.

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Pterosaur, meaning "winged lizard" (aka: pterodactyls), from the late Triassic to the end of the Cretaceous Period (220 to 65.5 million years ago).

Pterosaurs are the earliest vertebrates known to have evolved powered flight.

Archaeopteryx from the late Jurassic period (about 150 million years ago). This early bird could probably fly short distances.

Rhamphorhynchus was a Jurassic pterosaur.

Iberomesornis (From Spanish "Iberian" meaning "intermediate bird") was a small, early, toothed bird that lived during the early Cretaceous period. It was capable of sustained flight.

Pteranodon lived during the late Cretaceous period.

Ichthyornis (meaning "fish bird") a toothed, tern-like, powerful flyer from the late Cretaceous period.

Quetzalcoatlus, with a wingspan up to 36 ft., was among the largest flying animals ever. It lived during the late Cretaceous period.

Hatzegopteryx, with a wingspan up to 40 ft., was the largest flying animal ever identified (Although no complete fossil has been discovered)

Eoalulavis (from Spain) A very skilled, controlled flyer.